Search Results (10,439)

This study investigated the use of Marine Recyclable Aggregate (MRA), synthesized from Recycled Particles from Paste (RPPs) obtained from construction waste, seawater, and alkali activator (Na₂O∙3.3SiO₂, NS), for reinforcing marine soft clay. RPP is a laboratory-prepared material used to simulate construction waste. The physicochemical properties of MRA were characterized using X-ray diffraction (XRD), thermal field emission scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and thermogravimetric analysis (TGA). The results revealed that the key hydration products in MRA are Friedel’s salt (3CaO·Al₂O₃·CaCl₂·10H₂O, FS), xCaO·SiO₂·nH₂O (C-S-H), and CaO·Al₂O₃·2SiO₂·4H₂O (C-A-S-H). The formation of these hydration products enables MRA to maintain stability in marine environments. The deformation characteristics of MRA-reinforced soft clay under various conditions were investigated by integrating X-ray computed tomography with triaxial compression tests, allowing for the three-dimensional visualization and reconstruction of the failure process. The application of MRA for soft clay reinforcement in seawater environments enhances the bearing capacity of the clay and provided significant environmental benefits. Full article

Methane (CH₄), a significant greenhouse gas, ranks second only to carbon dioxide in its contribution to global warming. The application of Chinese herbs as a strategy to mitigate CH₄ emissions in ruminants has shown promise. However, there is limited information regarding the efficacy of Chinese herb straw in reducing CH₄ emissions in ruminants. This research aimed to investigate the beneficial effects of varying levels of Astragalus straw supplementation on methane emissions and to elucidate the underlying molecular mechanisms. The study examined the effects of different supplementation levels (0%, 5%, 10%, 15%, 20%) on in vitro rumen fermentation, CH₄ emissions, and ruminal microbial community in Lanzhou fat-tailed sheep using an in vitro fermentation method. The findings indicated that IVDMD, gas production, and CH₄ production significantly decreased with increasing levels of Astragalus straw supplementation (p < 0.05). Simultaneously, the lowest levels of AA, AA/PA, and NH₃-N, along with the highest concentrations of PA, BA, and MCP, were observed in the 20% supplementation group after 48 h of fermentation. In addition, supplementation with Astragalus straw resulted in an increased abundance of Bacteroidota, Spirochaetota, and Actinobacteriota, while decreasing the abundance of Firmicutes, Fibrobacterota, and Verrucomicrobiota. At the genus level, there was an observed increase in the abundance of Prevotella and Streptococcus, accompanied by a decrease in Rikenellaceae_RC9_gut_group. In conclusion, the supplementation of Astragalus straw has the potential to reduce CH₄ production by altering ruminal fermentation patterns, fermentation parameters, and microbial dynamics. Full article

Ammonia (NH₃) is a zero-carbon fuel and an attractive hydrogen (H₂) carrier for gas turbine power generation due to its high energy density, ease of storage, and transportation. This study numerically investigates NH₃/air combustion using a hybrid Well-Stirred Reactor (WSR) and Plug Flow Reactor (PFR) model in Cantera at pressures of 1–20 atm, temperatures of 1850–2150 K, and equivalence ratios (ϕ) of 0.7–1.2. The effects of pressure, equivalence ratio, and temperature on NH₃ conversion and NO formation are examined. Results show that NH₃ exhibits a non-monotonic conversion curve with pressure after the WSR, reaching a minimum near 5 atm, whereas NO formation decreases monotonically from 1 to 20 atm. Equivalence ratio sweeps show that NO decreases steeply as ϕ increases from 0.7 to ~1.1 as nitrogen is redirected toward N₂ and oxidizer availability declines; residual NH₃ increases rapidly for ϕ > 1.0, especially at high pressure. Increasing temperature accelerates NH₃ oxidation and raises NO formation, most strongly at low pressure where thermal and NH/OH pathways are least inhibited. These results indicate that co-tuning pressure and equivalence ratio near rich operation enables low-NO_x ammonia combustion suitable for advanced gas turbine applications. Full article

Excitable neurons are intrinsically capable of firing action potentials (AP), yet a state of hyperexcitability is prevented in the central nervous system by powerful GABAergic inhibition. For this inhibition to be effective, it must occur before excitatory signals can initiate runaway activity, implying the existence of a proactive control system. To test for such proactive inhibition, we used Ca²⁺ imaging and patch-clamp recording to measure how hippocampal neurons respond to depolarization and glutamatergic agonists. In mature hippocampal cultures (14 days in vitro (DIV)) and acute brain slices from two-month-old rats, neurons exhibited non-simultaneous responses to various excitatory stimuli, including KCl, NH₄Cl, forskolin, domoic acid, and glutamate. We observed that the Ca²⁺ rise occurred significantly earlier in GABAergic neurons than in glutamatergic neurons. This delay in glutamatergic neurons was abolished by GABA(A) receptor inhibitors, suggesting a mechanism of preliminary γ-aminobutyric acid (GABA) release. We further found that these early-responding GABAergic neurons express calcium-permeable kainate and AMPA receptors (CP-KARs and CP-AMPARs). Application of domoic acid induced an immediate Ca²⁺ increase in neurons expressing these receptors, but a delayed response in others. Crucially, when domoic acid was applied in the presence of the AMPA receptor inhibitors NBQX or GYKI-52466, the response delay in glutamatergic neurons was significantly prolonged. This confirms that CP-KARs on GABAergic neurons are responsible for the delayed excitation of glutamatergic neurons. In hippocampal slices from two-month-old rats, depolarization with 50 mM KCl revealed two distinct neuronal populations based on their calcium dynamics: a majority group (presumably glutamatergic) exhibited fluctuating Ca²⁺ signals, while a minority (presumably GABAergic) showed a steady, advancing increase in [Ca²⁺]i. This distinction was reinforced by the application of domoic acid. The “advancing-response” neurons reacted to domoic acid with a similar prompt increase, whereas the “fluctuating-response” neurons displayed an even more delayed and fluctuating reaction (80 s delay). Therefore, we identify a subgroup of hippocampal neurons—in both slices and cultures—that respond to depolarization and domoic acid with an early [Ca²⁺]_i signal. Consistent with our data from cultures, we conclude these early-responding neurons are GABAergic. Their early GABA release directly explains the delayed Ca²⁺ response observed in glutamatergic neurons. We propose that this proactive mechanism, mediated by CP-KARs on GABAergic neurons, is a primary means of protecting the network from hyperexcitation. Furthermore, the activity of these CP-KAR-expressing neurons is itself regulated by GABAergic neurons containing CP-AMPARs. Full article

The reliance on unstable hydrogen peroxide (H₂O₂) adversely affects the robustness and simplicity of chemiluminescence (CL)-based immunoassays. We report a novel external H₂O₂-free Fenton CL system integrated into a highly sensitive non-enzymatic immunoassay for the detection of SARS-CoV-2 nucleoprotein, utilizing cuprous–polyethylenimine–lipoic acid nanoflowers (Cu(I)-PEI-LA-Ab NF) as a non-enzymatic tag. The signaling polymer (PEI-LA) was synthesized via EDC/NHS coupling, which conjugated approximately 550 LA units to the PEI backbone. This polymer formed antibody-conjugated NF with various metal ions, and the Cu(I)-based variant was selected for its intense and sustained CL with luminol. The mechanism relies on an in situ Fenton reaction, in which dissolved oxygen is reduced by Cu(I) to H₂O₂, which reacts with oxidized Cu(II), producing hydroxyl radicals that oxidize luminol. Direct calibration of the SARS-CoV-2 nucleoprotein fixed on microplate wells demonstrated excellent linearity in the range of 0.01–3.13 ng/mL (LOD = 3 pg/mL). In a final competitive immunoassay format for samples spiked with the antigen, a decreasing CL signal that correlated with increasing antigen concentration was obtained in the range of 0.1–20.0 ng/mL, achieving excellent recoveries that were favorable compared with those of the sandwich ELISA kit, establishing this H₂O₂-independent platform as a powerful and robust tool for clinical diagnostics. Full article

Maintaining water quality and fish well-being in newly established, small, unfiltered betta (Betta splendens) aquaria is a significant challenge. To improve betta fish breeding and welfare, this study set up four groups: the Sagittaria subulata (S.su) group, the Alternanthera reineckii (A.re) group, the Wolffia globosa (W.gl) group, and the plant-free (CG) group. We evaluated the effects of aquatic plants on water quality, fish behavior, and microbial community in newly established tanks over 25 days. The results demonstrated that both the dissolved oxygen (DO) and potential of hydrogen (pH) decreased with the experimental duration, while ammonia nitrogen (NH₃-N) increased over time in all groups. Compared to the CG group, all aquatic plants significantly reduced the NH₃-N accumulation. The S.su group exhibited the lowest mean NH₃-N concentration of only 0.14 mg·L⁻¹, which was considerably lower than that of the other groups (p < 0.05). The behavioral analysis revealed that, during the 25-day randomized monitoring period, bettas in the S.su group exhibited the lowest surface breathing, with an average of only 0.36 events per 5 min, which was significantly lower than that of the CG group (p < 0.05). Additionally, the S.su and W.gl groups demonstrated longer average swimming durations than the other groups, suggesting a potential trend toward improved welfare in betta fish. Aquatic plants shaped the microbial diversity and composition within the experimental aquatic system. The W.gl group had the highest microbial diversity, and the A.re and S.su groups enriched Verrucomicrobiota. These results demonstrate the preferential shaping of microbial communities by aquatic plants, suggesting a potential pathway for enhancing water quality. In conclusion, S. subulata demonstrates the greatest benefits under the experimental conditions, making it a more suitable choice for this experiment. Full article

Pancreatic function tests are used to determine the presence of chronic pancreatitis, particularly in the early stage of the disease. Chymotrypsin is an indicator of pancreatic function and is thus related to pancreatic diseases. However, these methods often require specific equipment and cannot always meet on-site analysis requirements. Consequently, a highly sensitive detection method needs to be developed. This research employed graphene oxide modified with NHS sensors and peptides (RRHFFGC: Arginine-Arginine-Histidine-Phenylalanine-Phenylalanine-Glycine-Cysteine) tagged with gold nanoclusters (Au NCs) for the detection of chymotrypsin. The N-Hydroxysuccinimide-(Polyethylene Glycol)₄-Dibenzocyclooctyne (NHS-PEG₄-DBCO) and graphene oxide (GO)-N₃ click reaction yielded GO-NHS material, appropriate for fluorescence quenching. The peptide chain was accurately broken with the introduction of chymotrypsin, and the Au NCs were situated far from the GO-NHS surface. The detection limit was 2.014 pg/mL. The results showed that the detection method had high sensitivity in comparison with the previous studies. This method is relevant to real samples due to its potential efficacy. Therefore, it is a promising method in the biomedical field. Full article

This study is based on a long-term field trial with spring barley monoculture that was established in 1970 on Gleyic Fluvisol in the Žabčice, Czech Republic. The aim was to clarify the long-term impact of straw management and mineral nitrogen (N) application on grain yields and soil aggregate stability (SAS), and to determine the mineralogical and geochemical properties crucial for soil aggregate stability changes. Variants of the experiment included a combination of incorporated and harvested straw with doses of 0, 30, 60, and 90 kg N ha⁻¹ in the form of ammonium sulphate (NH₄)₂SO₄. The incorporated straw variants had a higher average grain yield of 0.51 t ha⁻¹. The SAS values were in the range 54–64% and increased in all variants with N application compared to the 0N control. Ammonium sulphate fertilisation caused soil acidification, which was not reduced even by the incorporation of straw. SAS increased with decreasing pH value, although cation exchange capacity and exchangeable Ca²⁺ decreased, and the soil organic carbon content was similar in all variants. The relatively high content of Fe- and Al-(oxo)hydroxides extracted with ammonium oxalate (Fe_ox and Al_ox) in all samples caused an increase in SAS due to decreasing pH in the N fertilised variants compared to the control. SAS should be considered in relation to other soil properties when evaluating soil quality and fertility. Full article

Excess nutrients in wastewater pose significant environmental risks, highlighting the need for low-cost treatment strategies that enable their removal. This study evaluated the adsorption capacity of woodchip biochar, a widely available waste material, for phosphate (PO₄³⁻), nitrate (NO₃⁻), and ammonium (NH₄⁺) in raw and secondary-treated wastewater, and compared the results against those obtained using synthetic solutions. Approach to equilibrium was reached quicker for NH₄⁺ (≈20 min) than for NO₃⁻ and PO₄³⁻ (≈40 min), with NH₄⁺ removal reaching up to 80% at a dosage of 20 g/L. Nutrient adsorption kinetics were best described by the pseudo-second-order model for the anionic species (NO₃⁻ and PO₄³⁻), while the pseudo-first-order model provided a better fit for the cationic species NH₄⁺. The Freundlich isotherm provided a good fit to the equilibrium data for all species, indicating the presence of heterogeneous adsorption sites. SEM–EDX and FTIR analyses confirmed nutrient adsorption onto the biochar surface and highlighted the involvement of carboxyl and hydroxyl functional groups, with FTIR showing the greatest spectral changes for NH₄⁺. Adsorption tests using secondary-treated wastewater showed high removal efficiencies (100% PO₄³⁻, 25.4% NO₃⁻, 89.5% NH₄⁺), whereas performance in raw wastewater was poor (maximum 32% NH₄⁺). Overall, woodchip biochar demonstrates strong potential as a tertiary treatment material, and its nutrient-saturated form may be reused as fertiliser, supporting nutrient recovery within a circular-economy framework. Full article

Background: Nipah virus (NiV), a zoonotic paramyxovirus with high case fatality and pandemic potential, remains without a licensed vaccine for humans to date. Although there has been progress in vaccine development, it remains limited, and peptide vaccines have rarely been validated in vivo. Methods: Here, we report the rational antigen selection, synthesis, and preliminary immunogenicity evaluation of NiV fusion glycoprotein (NiV-F)-derived linear peptides as vaccine candidates. Candidate epitopes were identified by in silico, and a total of 18 B- and T-cell epitope-derived peptides were shortlisted for synthesis and antigenicity validation by ELISA. Results: Antigenicity evaluation showed that 9 of the synthesized peptides have A_450nm of over 1 (8 from the F11 group, A_450nm: 1.13–3.6; 1 from the F18 group, A_450nm: 1.51), with the peptide constructs F11-3 (A_450nm: 3.5) and F11-4 (A_450nm: 3.6) showing the highest antigenicity. Interestingly, peptides from F11 with amidation increased antibody binding (F11-4-NH2, A_450nm: 3.05; F11-4-9mer-1-NH2, A_450nm: 0.87). The lead peptide candidates, F11-3 and F11-4, were subsequently used for the immunization experiment, and mouse sera were assessed against their homologous peptide antigens or recombinant NiV-F protein. ELISA result showed detectable antibody reactivity against their homologous antigen for the intramuscular (IM) F11-3 vaccinated group (A_450nm: 0.30 ± 0.35), whereas increased binding was observed for both IM-administered F11-3 (A_450nm: 1.62 ± 0.97) and F11-4 (A_450nm: 2.0 ± 0.77) against NiV-F protein, albeit without statistical significance compared to the negative control (NC, p > 0.05), and were markedly lower compared to mice immunized with NiV-F recombinant protein (PC, p < 0.01), underscoring the need for further optimization procedures. Conclusions: Collectively, these results support an exploratory antigen discovery and prioritization framework for NiV-F-derived peptide candidates and provide a foundation for future studies aimed at optimizing immunogenicity and evaluating protective relevance in appropriate preclinical models. Full article

This study developed high-performance anti-flashover silicone coatings using sol–gel-synthesized CaCO₃/SiO₂ hierarchical fillers optimized via L₁₆(4⁵) orthogonal design. The optimal filler (Sample 5) was prepared under 70 vol% ethanol, with nTEOS:nCaCO₃ = 1:1 and 0.2 mol/L NH₃·H₂O, at 45 °C, for 18 h, featuring covalent Si-O-Ca bonding, a dual-scale microstructure (2–4 μm CaCO₃ cores + 20–40 nm SiO₂ nodules), a 14.44 m²/g specific surface area, and bimodal porosity (8–80 nm). Composite C7 (30 wt% filler, 3 wt% KH-570, 1:2 resin-to-filler ratio) achieved superhydrophobicity (a 153° contact angle via Cassie-Baxter stabilization), ultrahigh electrical insulation (3.20 × 10¹⁴ Ω·cm volume resistivity, 1.60 × 10¹³ Ω surface resistivity), and robust mechanical properties (Shore 3H hardness, 5B adhesion). Standardized IEC 60507:2020 tests showed that C7’s flashover voltages (14.8 kV for KMnO₄, 14.3 kV for NaCl/KMnO₄, 13 kV for NaCl) exceeded that of neat silicone resin (NSR) and conventional CaCO₃-filled composite (SR-CC) by >135%. Additionally, C7 retained superhydrophobicity after 500 h UV aging and maintained a 124° contact angle after 12 months of outdoor exposure. The superior performance stems from synergistic hierarchical topology, tortuous discharge paths, and interfacial passivation. This work establishes a microstructure-driven design paradigm for grid protection materials in harsh environments. Full article

Activation of hepatic stellate cells (HSCs) featuring upregulated expression of α-smooth muscle actin (α-SMA) is recognized as a key driver for hepatic fibrosis, which provides a promising strategy for seeking anti-liver fibrogenic agents via suppressing the activation event. In this study, we designed and synthesized twenty-eight cordycepin derivatives through structural modifications at the C2 position and the C6-NH₂ group of the purine moiety. These compounds were screened for their inhibitory effects on HSC activation by detecting the mRNA expression of α-SMA using quantitative real-time polymerase chain reaction (qPCR) in the LX-2 cell model. Most compounds displayed inhibitory activity comparable to cordycepin, with compound 3a bearing a C2-chloro and a N6-methyl-N6-(2-chlorobenzyl) substituent, demonstrating enhanced in vitro anti-fibrotic effect. This compound was able to dose-dependently downregulate α-SMA and collagen-I at both mRNA and protein levels, inhibited LX-2 cell migration, and exhibited improved metabolic stability in liver microsomes. The Western blotting result also indicated that 3a could activate the AMPK signaling pathway. Overall, these results suggest 3a may serve as a lead compound for further investigation. Full article

Glycyrrhiza pallidiflora Maxim., a perennial legume with high biomass yield and good nutritional value, has potential as a forage resource. This study examined how mixing G. pallidiflora (C) with Leymus chinensis (Y) at varying ratios (C10Y0, C9Y1, C8Y2, C7Y3, C6Y4) affects silage fermentation, chemical composition, and microbial community structure. All treatments were inoculated with Lactiplantibacillus plantarum (1 × 10⁶ CFU/g fresh weight) and ensiled for 120 days. The results indicated that mixed silages markedly improved overall fermentation quality compared to the sole C silage (C10Y0). These mixed silages exhibited superior lactic acid (LA) concentrations, lower pH. Bacterial community profiling revealed that the addition of Y shifted the microbiota from a diverse community to one dominated by Lactobacillus. Although the C6Y4 and C7Y3 groups exhibited lower pH, they showed significantly elevated NH₃-N contents, while their crude protein contents and the relative abundances of Lactobacillus were both lower than those of the C9Y1 and C8Y2 groups. Considering the core requirements of comprehensive quality, the mixing ratios of 9:1 (C9Y1) and 8:2 (C8Y2) demonstrated the optimal effects: at these ratios, the silage maintained a CP content of 12.84–14.48% DM, with NDF and ADF contents stabilized at 47.55–51.09% DM and 33.67–34.14% DM, respectively, and DM content of 28.85–31.32%; in terms of fermentation quality, the pH value decreased from 4.85 in the sole C silage (C10Y0) to 4.04–4.11, the LA content increased from 13.91 g/kg DM to 28.86–30.87 g/kg DM, the LA/AA ratio rose from 1.31 to 3.37–3.97, and the NH₃-N content was reduced by 0.56–0.96% TN compared to the C10Y0 (decreasing to 4.16–4.45% TN), effectively inhibiting protein degradation; at the microbial level, the LAB count reached 9.03–9.05 log₁₀ CFU/g FM, an increase of 2.12–2.14 compared to the C10Y0, with a relative abundance exceeding 80%, successfully suppressing the proliferation of undesirable bacteria such as Raoultella and Weissella and ensuring fermentation stability. This provides technical support for utilizing this plant as a viable alternative forage resource. Full article

Ammonium nitrogen (NH₄⁺-N) removal and recovery from wastewater have been critical issues worldwide and key to achieving a sustainable nitrogen cycle and circular economy. In this study, we designed and constructed a pilot-scale air stripping system integrated with a nutrient-capture unit and evaluated the effective pH, temperature, and airflow conditions for maximising NH₄⁺-N removal and recovery from dairy processing wastewater (DPW). Our results demonstrated that increasing pH and temperature substantially enhances NH₄⁺-N removal via air stripping, with higher airflow rates further improving performance. Under these conditions (pH 11, 32 °C, and 300 L min⁻¹), NH₄⁺-N removal from synthetic wastewater reached ≈40% after 6 h air stripping. In comparison, real DPW exhibited slightly lower removal efficiency under the same conditions, achieving ≈34%, likely due to its more complex matrix. Additionally, incorporating a chemical precipitation step followed by filtration prior to air stripping removed NH₄⁺-N from DPW, achieving ≈43%. However, extending the stripping duration under identical conditions significantly improved removal performance, increasing NH₄⁺-N removal in DPW to ≈70%. The downstream capturing system, consisting of acid bath and granulated activated carbon (GAC), consistently recovered 70–95% of the released ammonia (NH₃) when even upstream NH₄⁺-N removal via air stripping was moderate. The GAC effectively adsorbed the volatilised NH₃, achieving adsorption capacities of up to ≈18 mg/kg. Overall, this integrated system demonstrates strong potential for simultaneous NH₄⁺-N removal and recovery from industrial wastewater streams, offering notable environmental benefits. Full article

Seven amidrazones containing a characteristic NH₂–N=C(Ar¹)–NHAr² moiety, where Ar¹, Ar² are phenyl, 4-methylphenyl, 4-nitrophenyl, 2-pyridyl, and 4-pyridyl substituents, denoted as 2a–2g, were synthesized by the reactions between thioamides and hydrazine. Their molecular structures were confirmed by ¹H, ¹³C, ¹H-¹³C HMQC, ¹H-¹³C HMBC, and ¹H-¹⁵N HMBC NMR spectroscopy, with complete assignment of the detected signals, as well as by high-resolution mass spectra. The biological activity of all compounds was studied, exhibiting antioxidant properties determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods, inhibitory potential against digestive tract enzymes (α-amylase, lipase, pepsin), cytotoxicity (hemolysis), and antimicrobial activities (against Gram-positive and Gram-negative bacteria, and a fungus). The antioxidant activity of the studied amidrazones varied from 83.34% to 93.27% and 1.01–5.79 mM FeSO₄ for the DPPH and FRAP methods, respectively. Moreover, these derivatives revealed inhibition potential against α-amylase (28.6–86.8%), lipase (28.0–60.0%), and pepsin (34.1–76.6%), which increased when increasing their concentrations from 0.2 to 1 mg/mL. Among them, compound 2d (possessing 2-pyridyl and 4-nitrophenyl substituents) stood out in particular, as a potent antioxidant (DPPH = 90.43%, FRAP = 4.73 Mm FeSO₄) with the highest activity against Gram-positive bacteria: S. aureus (MIC = 64 μg/mL), G. rubripertincta (MIC = 64 μg/mL), and fungus: C. albicans (MIC = 32 μg/mL); high α-amylase (86.8%) inhibition at the highest concentration (1 mg/mL); and lipase (38.0%) and pepsin (43.8%) inhibition at the lowest concentration (0.2 mg/mL). The obtained results were analyzed by unsupervised multivariate techniques to confirm significant differences in the biological activity of amidrazones depending on the Ar¹ and Ar² substituents. Full article